public class Student implements Comparable<Student>{
    public int age;

    public Student(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Student{" +
                "age=" + age +
                '}';
    }

    @Override
    public int compareTo(Student o) {
        return o.age - this.age;
    }
}
